Need more details (keyboard hardware, driver used, etc.) as that isn't a generic Win7 problem (runs fine here).

Samsung SDM4500P keyboard, nvidia 7300GT (latest driver), asus p5ld2-x/1333, core due duo e4500, 2 gb ram.

Did you try to run hedgewars on linux to see the difference?
In windows 7 did you run hedgewars with administrator priviledges or in normal mode?

As Hedgewars won't ask for elevation its run with default (non admin) privileges.

Which version of Hedgewars did you run? Did you try the latest and/or an older version as well? There shouldn't be any kind of input lag as long as you get some decent FpS (> 10).

I get 60 FPS all the time of playing, the version is .12

So you push some key, e.g. space, and it takes more than just some milliseconds for the game to respond? This sounds odd. I hope you're not talking about "jumping first and then continuing to run". That would be one of the small intentional lags to avoid people just hopping around etc.

the lag is evident when playing with rope, it's not a big lag but it's noticeable if compared to when playing on linux